Knockdown carpenter&#39;s square.



A. A. HARVIE.

KNOGKDOWN GARPENTERS SQUARE. APPLICATION FILED JAN. 23, 1911.

1,008,262. Patented Nov. 7, 1911.

2 SHBETSSHEET 1.

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ALBERT A. HARVIE, OF OTTUMWA, IOWA.

KNOCKDOWN CARPENTERS SQUARE.

To all whom it may concern:

Be it known that I, ALBERT A. HARVIE, a citizen of the United States, residing at Ottumwa, in the county of I/Vapello and State of Iowa, have invented certain new and useful Improvements in Knockdown Carpen ters Squares, of which the following is a specification.

This invention relates to a new and improved type of knockdown carpenters square, that is, one in which the tongue may be detached from the blade when desired, so that the two parts may be packed or transported separately.

I am familiar with certain forms of knockdown carpenters square, which, however, are so constructed that when the parts are disassembled a portion of the tongue still remains attached to or forms a partof the blade, so that the latter is not in the form of a straight bar of metal, but still has protruding from it sidewise a portion of the tongue. The main requirement for a. knockdown carpenters square arises because of the desirability of being able to pack such instrument in the smallest space possible and in the most convenient manner along with the other tools. Manifestly, then, a knockdown square which does not completely dis assemble, so that the parts are merely straight bars of metal, does not fulfil the requirement.

It will be understood that any form of carpenters square, in order to be perfectly serviceable, must be accurate at all times when in use as a square. Furthermore, when the tongue and blade are assembled, they must be united together with suflicient stiffness and rigidity to insure that they will stand up satisfactorily under severe usage without becoming inaccurate. It is evident that in any construction in which the tongue and blade may be set together or taken apart, a certain amount of wear will occur in the connection, so that there is a tendency for the parts to become inaccurate after a time.

The objects of the present invention are: to provide a knock-clown carpenters square of such construction that the tongue and blade will occupy no more space when disassembled and laid together than two similar bars of metal; to so relate the parts that they may be joined together without the use of special implements and without the necessity of using thumb-screws or the like, and

Specification of Letters Patent.

Application filed January 23, 1911.

Patented Nov. '7, 1911.

Serial No. 604,158.

at the same time to so form the parts that when the connection is made the square will be perfectly rlgid and serviceable; to so arrange the parts that they will automatically come together at exactly right angles each time they are assembled, notwithstanding the fact that a certain amount of wear will occur in the joint through service; to form the square from a minimum number of pieces. so that it may be cheaply constructed and will have permanency; and to so arrange the parts that when they are set together the surfaces of the joint will be perfectly flush.

Other objects and uses will appear from a detailed description of the invention, which consists in the features of construction and combination of parts hereinafter described and claimed.

Referring now to the drawings, Figure 1 shows a top view of the joint of the square, the two parts being separated a sufficient amount to show their construction; Fig. 2 is a bottom view, similar to that of Fig. 1; Fig. 3 is a top view of the entire square, with the parts joined together; Fig. 4 is'a cross section, taken on line H of Fig. 1, looking in the direction of the arrows; Fig. 5 is a cross section, taken on line 5-5 of Fig. '3, looking in the direction of the arrows, and showing the joint formed in such a way that as the parts wear this wear will be automatically taken up without impairing the angular accuracy of the square; Fig. 6 is a cross section taken on the line 66 of Fig. 3 looking in the direction of the arrows; and Fig. 7 is a cross section similar to Fig. 4, the parts being set together.

In the embodiment of my invention, I provide a spring tongue on one member, in position to properly engage the other member at one side of the same, and I then pro vide a locking boss on one of the members, and means for engaging the same on the other member, so that the spring tongue and locking boss, acting in opposition at opposite sides and edges of the members, will hold them rigidly together. In order that the parts may present flush surfaces at the joint, they should be properly grooved to receive the spring tongue and the locking boss.

By grooving the parts where they come together, so that the square as a whole will have flush surfaces when assembled, I am enabled to accomplish another result, namely, to compensate for wear in service while still keeping the parts in true angular position. This result I accomplish by beveling the edges of the grooves, so that the parts will merely settle down toward each other a little as they wear, so that the connection will always be a tight one and the parts will remain at exactly the proper angle.

Referring now to the figures, the numeral 8 designates the blade of the square, and the numeral 9 designates the tongue. In the construction illustrated, a groove 10 is cut across the top face of the blade, near its end, and the tongue is properly shouldered at 11, so that the edge 12 thereof will properly aline with the end edge 13 of the blade when the parts are set together. The tongue is sufliciently undercut at let so that when the parts are set together both their upper and lower faces will be practically flush. The edges 15 of the groove 10 are beveled downwardly toward each other, and the edges 16 of the tongue are correspondingly beveled, so that as the parts wear they will merely settle together a little closer each time, they being properly pro portioned to permit of this settling.

A locking boss 17 is provided on the blade near its edge, it being undercut so that when it engages a properly formed notch 18 in the end of the tongue the two parts will be held firmly together. It will be understood that the parts should be so proportioned that when the notch is forced into engagement with the boss the wedge shaped end of the tongue will fit squarely down into the groove of the blade. To hold the parts together at the other edge of the blade, I provide a spring tongue 19, preferably on the tongue itself, the spring end 20 of which fits into a notch 21 of the blade. This spring tongue serves to draw the parts tightly together at the inner edge of the blade, so that a tight connection is always maintained regardless of the wear which takes place on the edges of the groove 10.

The relative arrangement and co-action of the parts are well seen from Figs. 4: and 7, the latter of which shows the parts assembled. In order to facilitate seating the parts together, the end 22 of the tongue should be beveled, as shown in Fig. 7, inasmuch as it normally assumes a raised position, as shown in Fig. 4. Also, in order to secure the maximum amount of strength in the connection, the corner 23, where the end of the tongue is cut away, should be rounded, as shown in Fig. 7, and the edge of the blade should be correspondingly formed.

Referring now particularly to Figs. 5 and 6, I will describe more in detail the form of the groove 10, which is preferred in order to insure the maximum accuracy and tightness of the connection and to permit the maximum amount of wear. As hefore stated, the edges 15 of the groove are beveled, so that when the tongue is set in place its edges will strike these bevels before its lower surface comes in contact with the blade at the point 2st. It is preferred also that the central portion 25 of the groove should be rounded, as shown, and provided near its edges with flat surfaces 26, and that the end of the tongue should be correspondingly formed. The desirability of forming the parts in this way will be evident when it is considered that the only points where the tongue and the blade are drawn together are at the boss 17 and the spring tongue 20. These points are located practically on the center line of the tongue itself; and by forming the groove as just described the tongue may rotate slightly about its own center line in order to permit both its edges to seat squarely against the beveled edges of the groove, as heretofore described. As the edges of the groove wear slightly, the tongue will merely settle down a little farther, thus reducing the amount of the space 2%.

As illustrated in Fig. 5, the boss 17 takes the form of a separate block of metal, secured to the blade by means of a rivet 27. This should be a square rivet in order to prevent rotation of the block.

I claim:

1. In a device of the class described, the combination of a blade member provided adjacent one end thereof with a transverse groove having its edges beveled downwardly and inwardly toward each other, a tongue member having its end of suitable formation to seat in the groove and of a size to bring its edges into engagement with the beveled edges of the groove, and means for holding the end of the tongue member in engagement with the groove of the blade member, substantially as described.

2. In a device of the class described, the combination of a blade member provided adjacent one end thereof with a transverse groove having its side walls beveled downwardly and inwardly toward each other, a tongue member having its end of suitable formation to seat in the groove, and means for holding the end of the tongue member in engagement with the blade member, substantially as described.

3. In a device of the class described, the combination of a blade member provided adjacent one end thereof with a transverse groove having its side walls beveled downwardly and inwardly toward each other, and having the edge portions of its bottom face substantially flat and the central portion of said face being of convex curvature, a tongue member having its end of suitable formation to seat in the groove, and having its contacting edges beveled to properly engage the beveled edges of the groove, and

the edge portions of its lower face flat and the central portion of said face of concave curvature, and being of a size to bring its beveled edges into engagement with the beveled edges of the groove, and means for holding the tongue member in engagement with the blade member, substantially as de scribed.

4. In a device of the. class described, the combination of a blade member provided adjacent one end thereof with a transverse groove, a tongue member having its end of suitable formation to seat in the groove, and means for holding the tongue member in engagement with the blade member,,and comprising a locking device on one member adjacent one end of the groove and a. spring clamping device on the other member adjacent the other end of the groove, substantially as described.

5. In a device of the class described, the combination of a blade member provided adjacent one end thereof with a transverse groove, a locking stud centrally located near one end of the groove, a tongue member having its end portion of suitable formation to seat in the groove and the locking stud, and spring clamping means for holding the tongue member in engagement with the blade member adjacent the other end of the groove, substantially as described.

6. In a device of the class described, the combination of a blade member provided adjacent one end thereof with a transverse groove having its side walls beveled downwardly and inwardly toward each other, a locking stud on the blade member, centrally located with respect to the groove and adjacent one end thereof, a tongue member having its end portion of suitable formation to seat in the groove and the locking stud, and spring clamping means for holding the tongue member in engagement with the blade member adjacent the other end of the groove, substantially as described.

7. In a device of the class described, the

combination of a blade member provided adj acent one end thereof with a transverse groove, a tongue member having its end portion of suitable formation to seat in the groove, locking means for holding the end of the tongue member in engagement with the blade member, and a compression spring on the tongue member in position to seat in a recess in the face of the blade member opposite to the groove thereof, substantially as described.

ALBERT A. HARVIE.

Witnesses:

S. L. Vns'r, P. O. ACKLEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

